Distribution and abundance of phytoplankton in Hormuzgan province, Hormuz Strait and the Persian Gulf waters

Distribution and density of different phytoplankton groups in Hormuzgan province along the Persian Gulf, from Sirik Harbor to Nayband Bay were studied during winter 2004. Sampling was carried out on board of Ferdous-1 research vessel in seven transects (21 stations) in three lines including surface layer (0-20m), middle and bottom layers (20-50m and more than 50m, respectively). We found 46 genera of diatoms (Bacillariophyceae), 19 genera of dinoflagellates, 6 genera of blue-green algae (Cyanophyceae), 1 genus of Euglenophyceae and 1 genus of Chrysophyceae. We recorded maximum and minimum phytoplankton density in different transects at 37665583 and 2433208 cells/m3 respectively. The maximum density was 62762083 cells/m3 for Bacillariophyceae group that was sampled in surface layer (0-20m) of the station 9. Also, we found that average total number of phytoplankton in three lines of seven transects was 11728973 cells/m3. One way ANOVA showed a significant difference for average number of phytoplankton for each transect (P0.05)

Identification and density of ichthyoplankton in Laft Creeks (Hormuzgan province)

During a series of Ichthyoplankton survey from May 1998 to April 1999 Ichthyoplankton samples were collected at 12 stations in Laft creeks by 500 micron bongonet with oblique towing from bottom to water surface. Twenty-two families Ichthyoplanktons were identified (and two unidentified) during 12 months. Clupeiidae (31, 32%), gobiidae (26, 71%), scianidae (16, 55%), leiognathidae (11, 9%) were common and dominant families in all sampling stations. The creeks was divided in two branches: In east branch gobiidae (44.75%), clupeiidae (17.42%), scianida (13.5%) were more abundant than other families and in west branch clupeiidae (34.22%), gobiidae (23.77%), scianidae (16.34%) showed leiognathidae (13.26%) more abundance than other families, too. Some families e.g hemiramphidae, engrauilidae, blenidae, bothidae only occur in west branch, pleuronectidae family only occur in west branch. The highest density was found in winter season

Density and diversity of plankton population in eastern, central & western parts of Bandar Abbas

Forty three genera of phytoplankton and 22 population of zooplankton were distinguished in eastern, central and western coastal area of Bandar Abbas during one year study from June 1993 to July 1994. From the mentioned groups of planktons 35, 40 and 43 genera of phytoplankton and 18, 20 and 19 population 0f zooplankton were identified in eastern, central and western areas respectively. Western area had the most diversity and the highest density. Chrysophycea diatoms, had highest contribution in all areas. Western part showed highest diversity in winter with H = 3.98. Phylum Pyrophyta, Cyanophycea and Chlorophycea have had lowest contribution respectively. Cyanophycea were observed during warm months of July-August, while other phytoplanktons had (heir highest density during cold months. Zooplanktons were mainly Copepoda, Nauplius, Lamellibranchia, Prosobranchia, Tintinnidae and Foraminifera eggs and larvae of Gastropoda, Echinodermata and fishes were observed in all areas in low densities during few months. No significant difference was observed in density and diversity of zooplankton in all areas

Water quality assessment in inlet and outlet channels of shrimp farms in Tiab Area, Hormozgan Province

The shrimp farming industry has rapidly expanded in the south of Iran and in particular in the Hormozgan province during the past decade. We studied physico-chemical parameters of water in outlet and inlet channels of shrimp farms in Tiab during July-December 2000. Water samples were collected monthly at four stations during the harvest period. The parameters assessed included pH, salinity, dissolved oxygen, nitrate, nitrite, ammonia, phosphate, total phosphate, total suspended solids and chlorophyll a. The variation of above parameters were determined to be 7.62 - 8.19, 42.75 - 52.55ppt, 2.8 - 8.3mgil, 4.46 -0.66p,mil, 0.214 .64141, 0.12-2.0711m/1, 0.13-16.1 tili/1, 0.59-10.5 µm/l, 22-121 mg/1and 0.43-5.1311m/1 respectively. Results of the analyses showed that salinity, dissolved nutrient, T.S.S and chlorophyll a in the effluent were significantly higher than the influent water (P<0.05). A significant correlation was also found between chlorophyll a and nitrate, phosphate and suspended solid concentration (P<0.05). Comparison of the results with the standards showed that parameters are currently within acceptable limits

Study on biological factors for artificial reefs in Hormozgan Province (Bandar Lengeh area)

This study was carried out for growth of organism’s survey on artificial reef from 2004-2006 after establishment in Hormozgan offshore waters (Bandar Lengeh area). Also during this study we were examined some biological factors including: phytoplankton, zooplankton, ichthyoplankton and benthos from spring 2006 to winter 2006. In this study 43 phytoplankton genus were identified, 28 Bacillariophyceae (Diatom), 11 Dinophycea, 3 Cyanophycea and 1 Euglenaphycea. Bacillariophycea were dominant, Cyanophycea were high density observed in summer and Euglenaphycea was only observed in winter. The most abundant genus of diatoms were: Rhizosolenia, Navicula, Nitzschia, Coscinodiscus. Ceratium, Prorocentrum and Protoperidinium belong to Dinophycea, Oscillatoria belong to Cyanophycea were more than other genus. Copepoda and Nauplius were the most zooplankton and other group were respectively: Oikopleura, Polychaeta and Chaetognatha. The highest density of zooplankton was seen in winter. The statical study between different stations didn't show any significant (p>0.05). 6 ichthyoplankton families were seen and identified. These families were Clupeidae, Gobbidae, Callionymidae, Sparidae, Engraulidae and Scianidae. The high density were respectively in summer and spring. The highest annual mean belong to Gobbidae family. Benthos groups were including: Crustacea, Mollusca, Polychaete, Nematoda, Nemertin, Foraminifera, Opiouridae and Echiura. Annual high density of Crustacea were observed in spring season, Polychaete and Mollusca were observed respectively in summer and winter. Organisms which growth on the artifical reef were consist of 12 group. These Organism were Barnacle belong to Crustacea with one genus (Megabalanus tintinnabulum), Sponga with 5 families and Tunicate. The highest density was in 2005. We were seen increasing in size in some organisms such as Crab, Polychaetes, Bivalvia and Fish Larvae. Statical study didn't show any significant between organisms in different parts of artificial reef (top, mid, bottom) and kind of artificial reef had no effect on growth of organisms but Barnacles had high density on mixed artificial reef

The growth of faunal aquatics on artificial reefs in Bandar Lengeh Area, Persian Gulf

The growth of organisms on seven different artificial reef structures was surveyed from 2004-2006 in Hormuzgan offshore waters (Bandar Lengeh area). The organisms consisted of 12 groups the main of which included Barnacle (Megabalanus tintinnabulum), Sponges with five families and Tunicates. The highest density was observed in 2005, amounting to some 409.224g wet weight on each structure. However, a decrease was observed afterwards in the total mass of aquatics living on the structures. Some organisms such as crabs, polychaets, bivalves and fish larvae showed an increasing in size in the first year. Bivalves showed a decreasing trend in density but otherwise an increasing trend in size over time. Artificial shape of the reefs was not effective on the total density of the organisms living on the structures. Total density of live organisms on different parts of the artificial reefs (surface, middle and bottom) was not statistically significant (P>0.05). Numbers of crabs on mixed artificial reefs were higher than the other artificial reefs. This was also the same for barnacles

Assessment of mental workload air traffic controllers based on task load factors in air traffic control simulator

Background and aims: Air traffic control has known as a complex cognitive task, which requires controller to focus on task for long time. Mental workload plays an important role in the performance of controllers. The aim of this study was to assess the workload of air traffic controller on the basis of task load factors. Methods: The present descriptive-analytical study was conducted among fourteen air traffic controllers. First, air traffic control tasks were determined using hierarchical task analysis (HTA) technique and two low and high workload scenarios were designed based on the task load factors for controlling job. Next, the workloads of the controllers were assessed in these two scenarios by NASA-TLX inventory. Results: The results of HTA showed that air traffic control contains 49 main subtasks. The findings of the NASA-TLX showed that under high workload condition, mental demand with mean scores of 71/93 was the most overloaded task. Moreover, there were significant relationship between mental, physical, temporal demands, effort and frustration under high and low workload (p>0.05). Thus, it was not significant for performance variable under both low and high level conditions (p<0.05). Conclusion: The findings emphasize the importance of task load factors concerning air traffic controllers. Therefore, other evaluation methodologies is suggested with focused on the task load factors including Performance Assessment in all sectors of air traffic control center

The study characterization of morphology and abundance of zoea larval stages of two species of the family Epialtidae (Crustacea: Brachyura) in the coastal waters of Hengam Island (The Persian Gulf)

This research has been done on larval stage of two species of Epialtidae's Family on coastal waters of Hengam Island (The Persian Gulf) in 2011. Sampling is done by plankton net with 300 μm mesh size by method of diagonal traction from bottom to surface in 6 station for a year from winter 2011 to autumn 2012. This research is done based on morphological characteristics, such as overall shape and appendages of larvae in the lab by contrast phase inverted microscope of the first zoea larval stages of species Menaethuis monoceros and second zoea of Menaethiops nodulosus was studied. Larval species density studied at different stations and seasons were calculated. The highest average density respectively with 22/33 and 72/7 individual per m3 in the summer was calculated

An Ecology study on artificial reef in Hormozgan (Bandar Lengeh)

Uncontrolled fishing of marine resources in the world, has caused many commercial species to be at risk of destruction and extinction. Along with development of aquaculture, establishment of artificial reefs is considered one of important strategies to compensate loss of resources and overfishing. Accordingly, the project was based. Sampling of fish cary out from winter 2005 to Fall 2006 and for plankton, zooplankton, Iktyoplankton and bentoses from spring 2006 to winter 2006. The structures of Moloo artificial habitat had been arranged in seven rows at three depths (8, 9.5 and 11 m). Two control stations were considered one kilometer each side of the habitat. Sampling of physicochemical parameters and pollutantsand sediment cary out in summer and winter 2006 . CPUE and frequency of species, showed significant differences between seventh row (mixed structures) and six other rows (P0.05). Although mean CPUE showed high seasonal differences, but because analogous variance was also significantly different (P0.05). Observed and identified ichthyoplanktons were pertaining to families Clupeidae, Gobiidae, Callionymidae, Engraulidae, Sciaenidae and Sparidae. The highest density was observed in summer; The highest mean annual density was related to Gobiidae. Benthos groups were including crustaceans, molluscs, polychaetes, nematodes, nemertines, foraminiferans, ophiurids and echiurans. There were obtained no significant difference between density of benthic organisms on surfaces of different structures. Despite significant seasonal differences between some physicochemical factors and water pollution (P<0.05), significant differences between stations did not exist; Mean water temperature in establishment area of structures, were obtained 32.9 0.5 °C in summer and 21.4 0.5 °C in winter. Due to the buffering properties of seawater, pH had a limited range of changes (8 - 8.95) with an average of 8.81 0.13. Average amount of transparency was 3.8 2.72 and 5.63 0.78 m. in summer and winter respectively. Annual averages of dissolved oxygen and salinity were 7.11 0.1 ppm and 39.13 0.26 ppt respectively. Annual average of nutrients including nitrate, nitrite and phosphate in the study area, were, 74.9 0.7, 1.44 0.09 and 0.97 0.06 µmol per lit. respectively. The average COD in the summer and winter is estimated 1.53 0.48 and 1.62 0.48 mg per ml, respectively. Mean values of copper, zinc, iron, nickel and lead were obtained 26.5, 54.3, 27.6, 70.85 and 48.15 µg per one gram of dried weight of sediment, respectively; Aliphatic normal hydrocarbons (C10-C30) have been measured in water and sediment samples

Estimation of production potential in lake behind the Halilrud dam in Jiroft city

In order to the physical and chemical factors, planktons identification, determination of Chlorophylla and primary production in lake on study wad conducted, behind the Halilrud dam in Jiroft city. For this purpose 5 station selected and sampling was performed seasonally. Compersion of physical, chemical factors and planktons were done by duncan multiple test range. Studied factors had the suitable value for fish culture. In classes of Chrysophyceae, Bacillariophyceae and, Chlorophyceae had the most frequency respectively. Totally 49 phytoplanktons genus were identified which 18, 14,8,5 and 3 genus were related to Chlorophy ceae, Bacillariophyceae, Cyanophyceae, Dinophyceae and Chrysophyceae, genus respectively. Nitzchia and Navicula in Bacillariophyceae, Chlorococcum, Pediastrum, Staurastrum and Tetradron in Chlorophyceae, Spirulina, Chroococcus, Phormidium in Cyanophyceae and Dinobryon in Chrysophyceae had the most frequency. From Various group of zooplankton, Copepoda, Naplius, Cladocera, Rotifera (Brachinus, Keretella), Trichuridae were identified in winter season and Rotifera was the most of all. Chlorophylla had not significant difference in 9 seasons but it had significan difference in 5 depthes. Increasing in depth causes to decrease chlirophyla. The most chlorophylla was in 0.5m depth (4.7 mg/m3 ) and the least chlorophyllla was in 20m depth(0.82mg/m^3) primary production in lake was calculated by chlorophylla equal to 154 kg/ha/year